Method of liquefying chlorine



June 13, 1933. J. c. FALKENBERG 1,913,623

m METHOD OF LIQUEFYING CHLORINE Filed Aug. 11, 1950 72 7'0 COMPEL-550B Unrenlon- Patented June 13, 1933 um'rso srares earl-2N1, err-"ice minus c'HBIsTIAN FALKENBERG, or PARIS, FRANCE ammo]: or moons-me onnonms Application filed August 11, 1930, Serial No. 474,687, and'in Germany December 14, 1929.

As is well known, chlorine as produced by d An arrangement for carrying out the electrolysis must after compression be cooled method according to the invention is shown in condensers for converting it into the liquid by way of example and diagrammatically in state. In this case the cooling was efiected the accompanying drawing in elevation and M either by a refrigerating medium or by ordipartly in section.

nary cold water. The chlorine was cooled In the drawing 1 is a condenser to which is down to a temperature which was of necessity fed a mixture of chlorine gas and other gases several degrees, generally 5 to C. higher from any type of compressor, for instance, than the temperaturerof the refrigerating through a pipe 2 and at a suitable pressure,

10 medium. If the refrigerating 'medlum had for instance, 3 kg/cm above atmospheric for instance a temperature of 20 0., the pressure. Consequently the pressure in the chlorine could be cooled down to C. in interior of the condenser will also be the most favourable case. The chlorine was 3 kg/cm. According to the invention this never completely liquefied, in other words a chlorine gas mixture is passed to a second 15 portion of the gas passed out of the liquefying condenser 3. This second condenser consists v a paratus again, mixed with foreign ases. of a collecting vessel 4 for the liquid chlorine,

0 amount of the chlorine losses di ered into which the connection 5 between the first from one case to another. If a high compres-' condenser and the second condenser suitably sion pressure and very low temperatures were opens, and of a liquefying compartment, for employed, thechlorine losses were lower than instance a vessel 6 provided with suitable 70 at a smaller degree of compression and higher tubes 7. temperature. If, for instance, a refrigerat- According to the invention there is also proing medium of C. was available, the vided between the vessel 4 and the liquefying chlorine was cooled downto 15 C. and comcompartment, a trickling or dripping arpressed, for instance, to 3 kg/om above the rangement, for instance a vessel 8 containing atmospheric pressure. Under these condi- Raschig rings or the like 9. The lower part tions the loss of chlorine which passed away of the collecting vessel 4, in which the liquid with the waste gases amounted to about 34%, level is indicated at A, is connected by a ipe if the gas mixture umped into the condenser 10 havinga stop cock and throttle valve 11,

by the compressor hada urity of 90%. At with the interior of thevessel 6, while a furso the same time, a loss of 34% was the best rether pipe 12 serves for conveying awa chlosult obtainable with a theoretically perfect rine gases, the latter pipe being led to t e succhlorine liquefying apparatus. tion side of the chlorine compressor. In the By the method according to the invention vessel 6 there is also provided aspace 13 for it becomes possible either under the same collecting the non-liquefied portions of the working conditions as described above to re- -gas and from this space a pipe 14 with a duce the chlorine loss or, if the same chlorine throttle valve 15, leads away to the outside. loss is tolerated, with the same compression of The liquid chlorine can be tapped oif dithe chlorine gas to work ,at ll] her temperarectly from the vessel 4 into transport vessels, tures. The-advantage thus. 0 e'red consists as indicated at 16 and 17. either this, that there are smaller chlorine For special cases a connecting pipe may losses in the waste gases and consequently :1 also be provided between the condenser and better yield from the liquefaction, or if the the vessel 4, as indicated at 1 same amount of chlorine losses is to be 1501- The method operates as follows embed, it is possible to operate withia much The chlorine mixture flows through the smaller refrigerating machine which, as it pipe 5 out of the condenser 1 under a suitable has to operate at temperatures which are not pressure, for instance 3 kg/cm? and in this nearly so low, also consumes far low power vessel separation takes place between the liqthan the low temperature re igerating mauid chlorine and the gaseous constituent part chme formerly required. of the mixture. Alternatively the liquid chlomo rine may be introduced into the vessel 4 separate from the waste gases. In this case the pipe 18 is used for the introduction of the waste gases. In the spaces 4, 8, 7 and 13, there is exactly the same pressure as in the condenser 1. This pressure is regulated by the regulating valve 15. The pressure is kept for instance at 3 kg/cm. The chlorine mixed with the other gases flows out of the space 4 through the space 8 and through the condenser tubes 7, into the space 13, leaving the apparatus through the valve 15.

At the same time liquid chlorine flows through the pipe 10 andthe throttle valve 11 in the direction of the arrow 13 out of the vessel 4 into the vessel 6. The liquid chlorine which has been in the vessel 4, under a pressure of, for instance, 3 kg/cm, is expended in the vessel 6 to atmospheric pressure. In the vessel 4 at a pressure of 3 kg/cm the temperature will be +3 C. The temperature of the chlorine in the vessel 6 after 1 the expansion to atmospheric pressure drops to 34 C. The chlorine which, as already state above, sweeps out of the vessel 4 through the vessel 8 and through the tubes 7, is furthercooled down owing to the difierence in temperature between +3 C. and 34 (1, causing the greater part of the gaseous chlorine constituents to be condensed. The con densed chlorine trickles downwards in the tubes over the trickling members 9, into the space 8, meeting the rising chlorine gas and causing a recooling. The liquid chlorine which has come evaporated in the vessel 6 at a temperature 34 (3., leaves this vessel at a temperature of approximately --30 to -.-34 (1., through the pipe 12, that is to say in a relatively cold state. The gas leaving this vessel is pure chlorine gas without admixture of other gases. This gas is, therefore, in a particularly suitable state to be passed to the chlorine compressor where it can be used for producing an effective cooling of the cylinder shell ofthis compressor. Furthermore, by mixing this cold gas with the gas coming rom the electrolysis, the temperature of the mixture is considerably reduced and the degree of concentration of the mixture increased so that the compressor will work in a particularly favourable manner. What I claim is: A method of liquefying chlorine from a mixture of chlorine and pure-foreign gases by compressing and condensing, consisting in first preliminarily cooling the compressed chlorine gas mixture to a temperature which is sufliciently low for condensing a portion of the chlorine at the com ression pressure employed, thereupon col ecting the liquefied chlorine and tapping off the same into storage vessels, further coolm the remainder of the chlorine as mixture y an expanding portion of t e li uid chlorine obtained by the condensing, t e remainder being thereby 

